Found the vacuum leak-now what?

[chrisnsarah]

Well I moved some smog plumbing out of the way and tried the carb/choke cleaner trick again. BINGO. It's not along the top where the intake meets the head, but when I spray the intake bolt near the #4 cyl, the cleaner starts stalling the motor. I know the intake bolt holes are elongated, so maybe I misaligned something during assembly or the intake has a crack or warp maybe?
Well, if I have to pull off this intake, then I'm getting and aftermarket, Edelbrock probably.

[710 Burner]

You have answered your own question. Sure, you can try to goop something into the hole, but it will be temporary and may end up getting pumped through the motor.

[Crazy_Jeepman]

You have a bad seal on the intake gasket. You are going to need to replace that gasket again. You may have let that corner of that heavy intake drop down to hard and crush the intake gasket, damaging it, it happens. Once the ridge around each port in the gasket is crushed or damaged in anyway its junk. Trying to seal around the bolt will do nothing, as the bolts are outside of the sealing surface of the gasket, it would just pull vac from somewhere else if you do seal it.

[J20]

you could also try a cooper washer/ sealing washer that might help sealing it up.

[Crazy_Jeepman]

Originally posted by J20:
you could also try a cooper washer/ sealing washer that might help sealing it up.Why bother, it will just pull the leak from the underside of the intake. The intake gasket does not seal around the bolts anyhow, it seals between the bolts.

[scotty]

the thing that confuses me alittle is that vaccum leak will cause a lean running condition,as air is sneeking in thats not going past the venturis in the carb,and thus not having fuel mixed with it.

normally when you find vaccum leaks with propane or carb cleaner,the engine will idle up,as the substance finds its way in,it richens the air fuel mixture,causeing the engine to idle up. you must really have your carb richened up ALOT,to make the mizture rich enuff to cause the motor to try and stall :eek:

at any rate,try retorquing the intake bolts,and see if that helps any. if it doesnt,like the guys said, youre pretty much stuck with it till you can change the intake gasket :(

[chrisnsarah]

Well if I spray the carb/choke cleaner in the carb while the motor is running, it will almost stall, and that's always been my experience with carb cleaners.
Whether or not the motor revs up or bogs down depends on how big the leak is. On a small leak, the carb cleaner will form a temporary seal at the leak and RPM's will increase. I had this happen with a carb base gasket once. On a big leak, the carb spray will actually choke the A/F mixture as it is sucked in. I would think the propane would have the opposite effect since it's already "mixed" as it's sucked in.
I heard this theory from someone else, so I won't take credit for it.
I tried retorquing with no results.
BTW all the plugs are a nice tan/white color except for teh 2 near the leak which are bright white.
Since I have the edelbrock carb, might as well get the manifold.